Redirect a specific domain only

hello there,

I'm using traefik with docker and in my traefik.toml file I have currently this settings:

[[acme.domains]]
  main = "mydomain"
  sans = ["mydomain,shop-mydomain"]

, 

 [frontends.mydomain]
    backend = "mydmoain"
    passHostHeader = true
    [frontends.mydomain.routes.1]
      rule = "Host: mydomain,shop-mydomain"

 [backends.mydomain]
    [backends.mydomain.servers.1]
      url = "http://ipofmyapp:port"

How can I add a redirection if someone visits shop-mydomain he should instantly be forwarded to shop-mydomain/shop

I'm sorry I read through a lot of documentation but I couldn't find an example for what I'm trying to do.

And I had to strip my config a bit because new users can't post more than 4 links so I hope it's still understandable what I'm trying to do..